JPS628089Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electric wire, and more particularly to an electric wire suitable for a lead wire used in an electric device such as a motor.

In recent years, rotary compressors have come into widespread use as a driving source for cooling devices. In this type of compressor, the refrigerant is generally pressurized in a pressurizing chamber and then delivered to a condenser through an electric motor. On the other hand, electric motors are equipped with electric wires for supplying electric power, and most of these wires are made of metal-based conductors covered with a covering material or sleeve made of synthetic fibers and/or synthetic resin films. It is something that exists. Industrial standards have been established for the synthetic fibers and synthetic resin films used here. In the rotary compressor motors according to the present invention, polyester-based fibers or films, especially polyethylene terephthalate, are generally used. However, in rotary compressors that move the refrigerant through an electric motor, the chemical action of the refrigerant, such as Freon #22, converts the above polyester into low-molecular substances such as monomers and oligomers (generally MO and MO). ) is extracted, and this precipitates and accumulates in the area through which the refrigerant passes, resulting in
This often resulted in problems such as reducing the compression function of the compressor or blocking normal operation due to intake valve blockage. This tendency is particularly noticeable in fibers.

On the other hand, regarding polyester with a low MO content, for example, in Japanese Patent Publication No. 10368/1983, when manufacturing a polyester film, a polyester film is produced by drying a polymer chip under special conditions and then forming a film.
A method for reducing MO content is presented. However, the MO content in polyester is a component that occurs equilibrium in the molten state, and even if these methods reduce it at the polymer stage, the MO content will increase when it is molded into films or fibers. belongs to.

According to conventional knowledge, the MO content of polyethylene terephthalate yarn produced under normal conditions is 0.9 to 2.0%.

Furthermore, even if the film contains approximately 1% MO, its contact area with the refrigerant is much smaller than that of fibers, and as can be seen from the figure, due to the structure of the wire, it is difficult to contact the refrigerant. The MO content of the film is not an issue.

In view of these circumstances, the present invention focuses on fiber materials as a covering material, and uses polyester fibers that have been extracted from electric wires with organic solvents such as xylene and DMSO to suppress the MO content to a significantly lower amount than products normally obtained. shall be applied. That is, the electric wire of the present invention has the following configuration.

A linear material in which a fiber group mainly composed of polyester synthetic fibers covers a conductor, and the low molecular substance MO content of the polyester synthetic fiber group is 0.5.
% or less.

In the present invention, the important point is to suppress the MO content in the polyester synthetic fiber group to a range of 0.5% (weight) or less.

In other words, a small amount of polyester fibers
Even if there are fibers with an MO content of more than 0.5%, as long as the MO content of the fiber group as a whole is 0.5% or less, the purpose of the present invention is to avoid precipitation and adhesion of low-molecular substances such as monomers and oligomers. Deposition defects are improved. Specifically, for example, as shown in Example 1 described later, all the fibers in the fiber group may be composed of MO content of 0.5% or less, but 2 out of 8 threads
When using colored yarn, if the colored yarn is a normal polyester fiber dyed yarn and the MO content is 0.9%, and the other polyester fiber has an MO content of 0.3%, then [(0.9×2 )+(0.3×6)]/8, the MO content of the entire fiber group is 0.45%, and the purpose of the present invention is fully achieved.

The polyester synthetic fiber used in the present invention is preferably a polyethylene terephthalate homopolymer consisting of terephthalic acid and ethylene glycol, but a polyester synthetic fiber containing a part of the acid component is replaced with isophthalic acid, 2,6-naphthalene dicarboxylic acid, etc. Alternatively, a part of the glycol component may be replaced with butanediol, diethylene glycol, etc. Furthermore, a small amount of trifunctional compounds such as boric acid, trimellitic acid, and glycerin may be copolymerized.

Next, a method for measuring the MO content of synthetic fibers in the present invention will be described.

Cut the sample wire, remove the metal conductor, and take about 12 grams of the polyester braided coating, which is designated as sample A. After shaking this sample A with petroleum ether,
Vacuum drying was carried out at ℃ for 2 hours, and then left to cool in a desiccator for 1 hour.The resulting product was accurately weighed to the nearest 10 ^-3 grams, and the obtained value was defined as W1. Sample A was extracted by boiling in boiling xylene (138-139°C) for 24 hours,
Immediately thereafter, the sample was washed with xylene at about 100°C, vacuum dried at 160°C for 8 hours, cooled again in a desiccator for 1 hour, and weighed accurately in the same manner. The obtained value
The MO content is calculated using the formula below as W2.

MO content rate = (W1 - W2) / W1 × 100 ... (%) In this invention, the MO content rate of the wire coating material is set to 0.5
% or less, extraction treatment with an organic solvent is performed as described above. Regarding the extraction conditions, boiling point extraction using a specific solvent such as xylene or dimethyl sulfoxide (DMSO) is recommended, which allows effective MO extraction and does not cause deterioration or discoloration of the polyester thread.

By the way, in general, in the case of electric motors, for the purpose of preventing wiring errors during assembly, electric wires such as lead wires are made by interlacing colored threads in a covering material layer as identification markers. A combination of different colors is used. This colored thread is usually made by dyeing the same type of polyester thread as the covering material using a known method, and the function as a marker can be obtained by changing the color, number of cross-braids, structure, etc. of this colored thread. However,
When electric wires configured in this way are subjected to extraction treatment using an organic solvent as described above, in the case of dyed products, the dye is extracted at the same time and bleeds out, contaminating the white portion of the lead wire or turning it white, causing the marker function to deteriorate. This may cause problems such as loss of product value, such as loss of product value.
From ordinary electrical wires that already have identification markers,
When manufacturing the electric wire of the present invention, it is preferable to select an electric wire whose identification marker is made of spun-dyed polyester fiber. In other words, the coloring agent of dyed polyester is difficult to be extracted by the MO extraction solvent, whereas the coloring agent of polyester dyed by post-processing is easily extracted and loses its function as a marker.

The electric wire of the present invention does not need to be limited to such manufacturing method, and as a final product of the formed electric wire, the MO content of the fiber group as a whole excluding the film is 0.5%.
The following range is sufficient.

To explain the electric wire of the present invention with a diagram, the figure shows that the braided layer covering the conductor as the electric wire 5 is mainly composed of polyester synthetic fiber 1 which has been extracted in advance, and partially contains colored thread 2 of polyester fiber. Fiber Group 3 was used. Naturally, the MO content of fiber group 3 in this electric wire is 0.5
The range is below % by weight. Example 1 is an example in which a dyed yarn is used as the colored yarn 2 in this figure.

Since the present invention has the above-described configuration, it is an object of the present invention to provide an electric wire for a lead wire that is most suitable for a type of electric motor that circulates a refrigerant, such as a refrigerator, a freezer, an ice maker, a freezer, an air conditioner, etc. Can be done. This allows polyester monomer,
Troubles caused by oligomers (MO) etc. accumulating in the motor can be prevented, and contamination or decolorization of the electric wires can be prevented, so there is no need to worry about confusion when assembling the motor.

Example 1 Polyethylene terephthalate was melt spun and drawn to obtain a filament yarn of [η]=0.68, 100 denier 24 filaments. The MO content of this yarn is 1.3wt%. Also carbon black 0.5wt%
Polyethylene terephthalate blended with the above was similarly spun and drawn to produce a black spun-dyed filament yarn with [η] = 0.66, 100 denier 24 filament, and MO content of 1.4 wt%. Each of these yarns is 800T/m (S) from the bottom and 500T/m (Z) from the top.
100d/2 twine and pear were formed into small skeins weighing about 150g, dried in a vacuum dryer, then 60 small skeins and 20 kg of xylene were placed in a stainless steel pot, and boiling point extraction was performed using an electric heater. From room temperature to boiling point (138℃)
It took 1.5 hours to raise the temperature, and the extraction time was 9 hours. After deliquing and drying, the small skeins were rewinded and wound into cone paper tubes each weighing 150 g. The MO content of the twine obtained was 0.3 wt% in all cases, and the color of the dyed yarn did not fade. Using the low-MO twine thus obtained, an electric wire coated with a 3 mm diameter copper stranded wire was manufactured using a Watson type braiding machine.
The yarn spool had 2×8 yarns, the yarn feeding speed was 30 m/hr, and the wire winding speed was 20 m/hr, and black yarn was used as a marker for 2 of the 8 yarn spools. The composition of the electric wire (weight ratio per 300m) is as follows.

Conductor wire (copper) 12.0Kg Insulating film (polyethylene terephthalate) 0.5Kg Covered thread 3.5Kg Total 16.0Kg The MO content of this wire was determined using the above method.
It was 0.4wt%. Note that the insulating film used here has not been subjected to low MO treatment, and its MO
The content was 1.1wt%.

Comparative Example 1 An electric wire produced in exactly the same manner as in Example 1 except that polyethylene terephthalate yarn before extraction treatment was used had an MO content of 1.3 wt%.

Comparative Example 2 The same process as in Example 1 was carried out except that the extraction process was carried out below the boiling point of trichlorethylene.
The MO content of the electric wire using this polyethylene terephthalate fiber was 0.7 wt%.

[Brief explanation of the drawing]

The figure is a perspective view showing an example of the electric wire according to the present invention. DESCRIPTION OF SYMBOLS 1... Polyester thread, 2... Polyester colored thread, 3... Braided covering fiber group, 4... Conductor, 5
...Electric wire, 6...Insulating film (polyester).

Claims (1)

[Scope of utility model registration request] A fiber group consisting mainly of polyester-based synthetic fibers is a linear material covering a conductor, characterized in that the low-molecular substance MO content of the polyester-based synthetic fiber group is 0.5% or less. Electrical wire.